"Was cyclist who killed CBS executive's wife using a fitness app that turns every journey into a race? He had top rankings on 'Strava' site.

Jason Marshall crashed into Jill Tarlov while riding through Central Park She was left brain dead by the collision and died on MondayMarshall, 31, is said to be an avid user of the racing app called Strava It uses GPS so riders can race each other over stretches of road The saxophonists had completed four 'fastest time achievements' in New York before the tragic collision There have been two lawsuits associated with the app in the last four yearsMarshall has not been charged with any crime but police are still investigating the incident

The cyclist whose collision with a CBS executive's wife ultimately led to her death is believed to have top ratings on a fitness app which allows users to race each other.

Jason Marshall, 31, who hit 59-year-old Jill Tarlov while she was walking through Central Park last Thursday, is said to be an avid user of Strava, a service which allows riders to challenge one another and share their locations via GPS.

It has a ranking system where cyclists can record their times over 2.5million different routes in a bid to become KOM - or King Of The Mountain - or complete various 'achievements'."